BOGOTÁ, Colombia — The suspect in a car bombing that left 21 people dead on Thursday in Bogotá, the capital,was a member of the country’s largest remaining guerrilla group, the defense ministry said Friday.
José Aldemar Rojas Rodríguez, the assailant who was also killed in the attack, was a member of the National Liberation Army, a Marxist rebel group known as the ELN, said Guillermo Botero, the Colombian defense minister.
The group did not claim responsibility for the bombing, but it has stepped up attacks against the government since its rival, the Revolutionary Armed Forces of Colombia, or the FARC, signed a peace deal with the government in 2016.
Thursday’s attack was the first car bombing in Bogotá in years, a gruesome reminder of a time when drug lords and rebel groups ravaged the capital’s streets with car bombs, killing hundreds of civilians and members of the security forces. Since the signing of the peace accords, the Colombian government has said it turned the page on that violent era.
Scenes of the carnage tell a different story. Cellphone videos shared with The New York Times on Friday and filmed by someone who was at the scene showed a burning vehicle with a dismembered torso in blue pants sprawled in front of the flames. The camera also captured images of a human foot and what appeared to be a severed head. Rescue workers struggled to carry survivors out on stretchers.
The attack against security forces in Colombia’s center of power marked an escalation of hostilities with the ELN, which in the last year has bombed police stations, attacked oil pipelines and kidnapped soldiers, police officers and military contractors. And it will almost certainly derail negotiations with the group, which says it is seeking a similar peace deal as the FARC, said Jairo Libreros, a professor at Externado University in Bogotá and a security analyst who tracks the group.
“This closes the window and ends all chance in the short term of peace talks,” Mr. Libreros said. “Citizens will not tolerate peace negotiations at a time of attacks.”
Iván Duque, Colombia’s president, who had been away from the capital, called the bombing a “miserable terrorist act” and said that he was returning to direct the investigation. “All Colombians reject terrorism and are united to confront it,” he said on Twitter.
The car had been laden with about 175 pounds of pentolite, a powerful explosive, which went off minutes after a promotion ceremony for police officers, according to the office of the Colombian attorney general.
“This kind of thing has an impact,” said Jenifer Beltrán, 36, a mother of two who was home when she heard the explosion. “It makes you think that once again the country is headed toward that memory of those years when there were so many car bombs and attacks everywhere.”
By midday Thursday, relatives of students of the Santander General School had gathered by the building to search for their loved ones.
Among them was Leonor Pardo, a saleswoman whose 21-year-old son had been studying at the academy and had just been found unharmed.
“We heard an explosion — it was horrible because the first thing I thought of was my son,” said Ms. Pardo, who was near the police academy at the time. “I fainted.”
Even before Mr. Botero spoke on Friday, local news reports speculated that the bombing may have been the work of Colombia’s remaining guerrilla fighters, many of whom remain at large.
Last January, guerrilla fighters of the National Liberation Army killed five police officers and wounded more than 40 in the bombing of a police station in the port city of Barranquilla.
The group also kidnapped four soldiers, three police officers and two military contractors last year in a bid to pressure the government to enter into peace talks. The hostages were released, but the government refused to negotiate.
The attack was a blow to Mr. Duque, whose approval ratings as president have fallen in recent months, particularly on issues of security.
“I think this comes at a critical juncture for Duque’s early government,” said Arlene B. Tickner, a political scientist at Bogotá’s Del Rosario University who writes a column in El Espectador, a Colombia newspaper. “He’s not high in the polls, he’s subject to ridicule in some circles and under tremendous pressure on security.”
Under pressure from his own right-wing Democratic Center party, Mr. Duque recently replaced the heads of the national police and armed forces with hard-liners and promoted other top military officials who had been linked to extrajudicial killings, according to Human Rights Watch.
“The decision to appoint officers linked by credible evidence to serious abuses conveys the toxic message to the troops that respect for human rights is not necessary for career success,” said José Miguel Vivanco, the head of Human Rights Watch’s Americas division.
Among the witnesses on Thursday was Berta Poussaint, 62, who sells military uniforms near the school. Rather than using this as a call for a crackdown, she said, the authorities should try to negotiate with guerrilla groups.
“The president needs to push for peace,” said Ms. Poussaint.